A fuzzy integrated non-linear backstepping control of a grid connected PMSG wind farm

Abstract

In this paper a grid connected PMSG wind farm is controlled by non-linear backstepping control. The PMSG power is delivered to grid through two back-to-back connected IGBT based VSCs. The VSCs are controlled by individual Sin PWM techniques for which the reference signals are generated non-linear backstepping controller. A capacitor is connected at the common DC link of the back-to-back VSCs for voltage stability. The backstepping controller designed for the control of PMSG has the capability to extract maximum power from the wind farm. The machine side connected VSC operates in synchronization to the rotor angle and the grid side connected VSC operates in synchronization with the grid voltages. The DC voltage regulator of the grid side converter control should be optimum for better stability of the system. Therefore, the conventional PI controller of the voltage regulator is replaced by a 49-rule base FLC which reduces the ripple and settling time of the DC link voltage. A 2MG PMSG wind farm is considered for performance analysis with PI and FLC in the non-linear backstepping control structure. The comparative analysis is carried out in MATLAB software with Simulink block sets utilized to design the wind farm connected to grid. The graphs are compared to determine the performance of the controller with different operating conditions.